When I first wrote about channel swapping in Lightroom back in 2018, Adobe had recently introduced the export and import of the LUT tables from Photoshop to Adobe Camera Raw (ACR.) It was a new and novel way of achieving false-colored infrared images.
Although I presented a functioning process to create camera profiles with the red and the blue channels swapped, I now realize that the explanations could have been clearer. Additionally, ACR has changed, offering alternative ways of creating the channel swap, even directly in Lightroom. In this post, I will explain how to swap the red-blue channels for infrared photographs in Lightroom. Creating a camera profile with the red and blue channels swapped will wait for a later post.
Don’t let the length of this post make you think that this is a complicated process. It is not; I simply want to explain the process in detail.
First Thing First
When you try to adjust the white balance of an infrared frame, you will notice that the Temperature slider does not have enough room to move more to the left. We need to find a way to shift the slider scale so that the adjustment slider can move more to the left. That can be done using a hard-to-find Adobe application called DNG Profile Editor. I make both Windows and Mac versions available here if you cannot find them on the Adobe site. Please bear in mind, these are Adobe products, downloaded from Adobe sites a long time ago. I make them available for your convenience. The Mac version is courtesy of Dan Waterman.
Export a DNG Image from Lightroom
As implied in its name, this program needs a file in Adobe DNG (digital negative) format.
- Start Lightroom and navigate to the folder where you keep your infrared photographs
- Select one, and right-click on it to display the context menu
- Find the “Export” option and then “Export to DNG“
- Put the new file in a folder you can easily find
Start the DNG Profile Editor
- From the top menu, follow “File/Open DNG Image”
- Navigate to the folder where you filed the exported DNG image
- Open the image
Shift the Temperature Range
Being from the same stable as its more famous siblings, DNG Profile Editor will recognize the camera and related profiles to it by reading the image data. Among the profiles offered for Canon EOS M5, I chose Camera Standard. I am not exactly sure if this is necessary but being systematic will help. You will find the camera profiles under the Color Tables tab. Click the image on the left to see.
We need to give the new profile with a shifted temperature scale a name. Select the Options tab. In the Profile Name field, enter a descriptive name. I chose Camera Standard WBC Temp -100 to indicate the starting point and the adjustment made in the profile editor. Click the image on the left to see.
Now, choose the Color Matrices tab and move the Temperature slider under White Balance Calibration block all the way to the left to -100. Don’t worry about how the image looks, we will only save the adjustment. That’s all you need to do. Click the image on the left to see.
From the menu, choose File/Export <camera name> Profile. On my setup, it read Export Canon EOS M5 profile. It will suggest saving the new profile in the correct folder for ACR and Lightroom to read, accept the destination. Click the image on the left to see. On Windows this folder is:
C:\Users\<user name>\App Data\Roaming\Adobe\Camera Raw\Camera Profiles
You can now close the profile editor; it has done its job of shifting the temperature adjustment scale to the right. You will see it when you start Lightroom and select the new camera profile.
When you start Lightroom and browse the profiles for a photograph taken with that camera, you will see the new profile as an option. This by itself will be of significant help even if you do not want to swap the channels. When you choose this new profile and look at the White Balance block, you will notice that the Temperature slider is positioned significantly to the right, allowing for a wide range of adjustments. Below are the new camera profile and the new location of the temperature slider.
Swap R-B Channels in Lightroom – Option 1
Both Lightroom and Adobe Camera Raw now have a feature that will effectively shift the red and blue channels. This is straightforward and simple. I will present this, then offer two other alternatives for similar but not identical results.
Hue Mapping to Swap the R-B Channels
The latest versions of Lightroom have a Hue Shift, or Hue Map slider but it is available in local adjustments like Graduated or Radial Fill and the Adjustment Brush. The easiest way to apply the hue shift to the entire image is by using a Graduate Fill. Here are the simple steps:
- Click on the Graduated Fill to pick up the tool
- Move the mouse cursor just outside any edge
- Click and hold the Shift key then click and hold the left mouse button and drag away from the image edge outward which will apply the adjustments made to the area inside the image. You don’t need to move more than a tad. See the first image below, note the direction of the arrow.
- Now, look for the colorful Hue mapping slider with two bars, one stationary and one moving
- The points on the hue sliders are mapped to the exact colors, the top being the target and the sliding bottom as the source hue. Move the source slider all the way to the right or left.
- This will remap the colors, essentially swapping the red and the blue channels
- You are done!
You can now adjust the temperature and tint sliders of the white balance panel to get the result you want. Keep in mind that the sliders will do the opposite of what you expect. This is true in the Temp and Tint sliders as well as the Hue-Saturation-Luminance adjustments.
Create a Lightroom Preset
The repetition of the same steps can be time-consuming and potential sources of mistakes. So, you can at least create a preset in Lightroom to make this happen with a single click on the preset name.
Make sure that the following steps are done with no other adjustment to have a clean profile selection and channel swapping.
- If your import sequence does not apply a particular camera profile, select the profile you created from the Browse button in the basic channel
- Add the Graduated Filter and apply the hue shift as described above
- On the left-hand side, find the presets panel and click on the plus sign at the top of it to create a new preset
- Click on the “Check None” button to make sure nothing else gets saved
- Select a group to contain the new preset
- In the top field, enter the name of the preset
- Put checkmarks in “Treatment & Profile” and “Radial Filters” boxes
- Click on the “Create” button and save it
Pros and Cons of Option 1
The best thing going for this approach is the simplicity and everything being done in Lightroom. If this works, why do we need to have two other ways of doing the same thing? First, different strokes, for different folks. Second, doing this in a camera profile will not bring any local adjustments with it and the level of camera profiles are adjustable. Third, there is indeed a subtle visual difference between doing this with actual channel swap in Photoshop and using the hue shifter in Lightroom or Adobe Camera Raw.
The next post explains an alternative method for doing it in Adobe Camera Raw, and the third one will revisit the actual channel swap in Photoshop. Trust me, this time I will explain it more clearly.